Language deprivation experiments

Last updated

Language deprivation experiments have been attempted several times through history, isolating infants from the normal use of spoken or signed language in an attempt to discover the fundamental character of human nature or the origin of language.

Language Capacity to communicate using signs, such as words or gestures

Language is a system that consists of the development, acquisition, maintenance and use of complex systems of communication, particularly the human ability to do so; and a language is any specific example of such a system.

Human nature is a bundle of characteristics, including ways of thinking, feeling, and acting, which humans are said to have naturally. The term is often regarded as capturing what it is to be human, or the essence of humanity. The term is controversial because it is disputed whether or not such an essence exists. Arguments about human nature have been a mainstay of philosophy for centuries and the concept continues to provoke lively philosophical debate. The concept also continues to play a role in science, with neuroscientists, psychologists and social scientists sometimes claiming that their results have yielded insight into human nature. Human nature is traditionally contrasted with characteristics that vary among humans, such as characteristics associated with specific cultures. Debates about human nature are related to, although not the same as, debates about the comparative importance of genes and environment in development.

The evolutionary emergence of language in the human species has been a subject of speculation for several centuries. The topic is difficult to study because of the lack of direct evidence. Consequently, scholars wishing to study the origins of language must draw inferences from other kinds of evidence such as the fossil record, archaeological evidence, contemporary language diversity, studies of language acquisition, and comparisons between human language and systems of communication existing among animals. Many argue that the origins of language probably relate closely to the origins of modern human behavior, but there is little agreement about the implications and directionality of this connection.


The American literary scholar Roger Shattuck called this kind of research study "The Forbidden Experiment" because of the exceptional deprivation of ordinary human contact it requires. [1] Although not designed to study language, similar experiments on non-human primates (labelled the "Pit of despair") utilising complete social deprivation resulted in psychosis.

United States Federal republic in North America

The United States of America (USA), commonly known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is slightly smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U.S. is the third most populous country. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico. The State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The extremely diverse geography, climate, and wildlife of the United States make it one of the world's 17 megadiverse countries.

Roger Whitney Shattuck was an American writer best known for his books on French literature, art, and music of the twentieth century.

Pit of despair

The Pit of despair was a name used by American comparative psychologist Harry Harlow for a device he designed, technically called a vertical chamber apparatus, that he used in experiments on rhesus macaque monkeys at the University of Wisconsin–Madison in the 1970s. The aim of the research was to produce an animal model of clinical depression. Researcher Stephen Suomi described the device as "little more than a stainless-steel trough with sides that sloped to a rounded bottom":

A ​38 in. wire mesh floor 1 in. above the bottom of the chamber allowed waste material to drop through the drain and out of holes drilled in the stainless-steel. The chamber was equipped with a food box and a water-bottle holder, and was covered with a pyramid top [removed in the accompanying photograph], designed to discourage incarcerated subjects from hanging from the upper part of the chamber.

In history

Ancient records suggest that this kind of experiment was carried out from time to time. An early record of an experiment of this kind can be found in Herodotus's Histories . According to Herodotus, the Egyptian pharaoh Psamtik I carried out such an experiment, and concluded the Phrygian race must antedate the Egyptians since the child had first spoken something similar to the Phrygian word bekos, meaning "bread". [2] However, it is likely that this was a willful interpretation of their babbling. [3] [4]

Herodotus Ancient Greek historian

Herodotus was an ancient Greek historian who was born in Halicarnassus in the Persian Empire. He is known for having written the book The Histories, a detailed record of his "inquiry" on the origins of the Greco-Persian Wars. He is widely considered to have been the first writer to have treated historical subjects using a method of systematic investigation—specifically, by collecting his materials and then critically arranging them into an historiographic narrative. On account of this, he is often referred to as "The Father of History", a title first conferred on him by the first-century BC Roman orator Cicero.

<i>Histories</i> (Herodotus) book by Herodotus

The Histories of Herodotus is considered the founding work of history in Western literature. Written in 440 BC in the Ionic dialect of classical Greek, The Histories serves as a record of the ancient traditions, politics, geography, and clashes of various cultures that were known in Western Asia, Northern Africa and Greece at that time. Although not a fully impartial record, it remains one of the West's most important sources regarding these affairs. Moreover, it established the genre and study of history in the Western world.

Ancient Egypt ancient civilization of Northeastern Africa

Ancient Egypt was a civilization of ancient North Africa, concentrated along the lower reaches of the Nile River in the place that is now the country Egypt. Ancient Egyptian civilization followed prehistoric Egypt and coalesced around 3100 BC with the political unification of Upper and Lower Egypt under Menes. The history of ancient Egypt occurred as a series of stable kingdoms, separated by periods of relative instability known as Intermediate Periods: the Old Kingdom of the Early Bronze Age, the Middle Kingdom of the Middle Bronze Age and the New Kingdom of the Late Bronze Age.

An experiment allegedly carried out by Holy Roman Emperor Frederick II in the 13th century saw young infants raised without human interaction in an attempt to determine if there was a natural language that they might demonstrate once their voices matured. It is claimed he was seeking to discover what language would have been imparted unto Adam and Eve by God.

Frederick II, Holy Roman Emperor 1194 – 1250, Holy Roman Emperor of the Middle Ages

Frederick II was King of Sicily from 1198, King of Germany from 1212, King of Italy and Holy Roman Emperor from 1220 and King of Jerusalem from 1225. He was the son of emperor Henry VI of the Hohenstaufen dynasty and of Constance, heiress to the Norman kings of Sicily.

Feral child human child who has lived isolated from human contact from a very young age

A feral child is a human child who has lived isolated from human contact from a very young age, and so has had little or no experience of human care, behavior or human language. There are several confirmed cases and other speculative ones. Feral children may have experienced severe abuse or trauma before being abandoned or running away. They are sometimes the subjects of folklore and legends, typically portrayed as having been raised by animals.

In neuropsychology, linguistics, and the philosophy of language, a natural language or ordinary language is any language that has evolved naturally in humans through use and repetition without conscious planning or premeditation. Natural languages can take different forms, such as speech or signing. They are distinguished from constructed and formal languages such as those used to program computers or to study logic.

The experiments were recorded by the monk Salimbene di Adam in his Chronicles, who wrote that Frederick encouraged "foster-mothers and nurses to suckle and bathe and wash the children, but in no ways to prattle or speak with them; for he would have learnt whether they would speak the Hebrew language (which he took to have been the first), or Greek, or Latin, or Arabic, or perchance the tongue of their parents of whom they had been born. But he laboured in vain, for the children could not live without clappings of the hands, and gestures, and gladness of countenance, and blandishments." [5]

Salimbene di Adam Franciscan friar and historian

Salimbene di Adam, O.F.M., was an Italian Franciscan friar, theologian, and chronicler who is a source for Italian history of the 13th century.

Hebrew language Semitic language native to Israel

Hebrew is a Northwest Semitic language native to Israel; the modern version of which is spoken by over 9 million people worldwide. Historically, it is regarded as the language of the Israelites and their ancestors, although the language was not referred to by the name Hebrew in the Tanakh. The earliest examples of written Paleo-Hebrew date from the 10th century BCE. Hebrew belongs to the West Semitic branch of the Afroasiatic language family. Hebrew is the only living Canaanite language left, and the only truly successful example of a revived dead language.

Greek language language spoken in Greece, Cyprus and Southern Albania

Greek is an independent branch of the Indo-European family of languages, native to Greece, Cyprus and other parts of the Eastern Mediterranean and the Black Sea. It has the longest documented history of any living Indo-European language, spanning more than 3000 years of written records. Its writing system has been the Greek alphabet for the major part of its history; other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems.

Several centuries after Frederick II's experiment, James IV of Scotland was said to have sent two children to be raised by a mute woman isolated on the island of Inchkeith, to determine if language was learned or innate. [6] The children were reported to have spoken good Hebrew, but historians were skeptical of these claims soon after they were made. [7] [8] This experiment was later repeated by the Mughal emperor Akbar, who held that speech arose from hearing, thus children raised without hearing human speech would become mute. [9]

James IV of Scotland King of Scots

James IV was the King of Scotland from 11 June 1488 to his death. He assumed the throne following the death of his father, King James III, at the Battle of Sauchieburn, a rebellion in which the younger James played an indirect role. He is generally regarded as the most successful of the Stewart monarchs of Scotland, but his reign ended in a disastrous defeat at the Battle of Flodden. He was the last monarch from the island of Great Britain to be killed in battle.

Muteness or mutism is an inability to speak, often caused by a speech disorder or surgery. Someone who is mute may be so due to the unwillingness to speak in certain social situations.

Inchkeith island in the Firth of Forth, Scotland

Inchkeith is an island in the Firth of Forth, Scotland, administratively part of the Fife council area.

In fiction

See also

Related Research Articles

Sign language Language which uses manual communication and body language to convey meaning

Sign languages are languages that use the visual-manual modality to convey meaning. Language is expressed via the manual signstream in combination with non-manual elements. Sign languages are full-fledged natural languages with their own grammar and lexicon. This means that sign languages are not universal and they are not mutually intelligible, although there are also striking similarities among sign languages.

French Sign Language Sign language used predominately in France and French-speaking Switzerland

French Sign Language is the sign language of the deaf in France and French-speaking parts of Switzerland. According to Ethnologue, it has 100,000 native signers.

Babbling stage in child development

Babbling is a stage in child development and a state in language acquisition during which an infant appears to be experimenting with uttering articulate sounds, but does not yet produce any recognizable words. Babbling begins shortly after birth and progresses through several stages as the infant's repertoire of sounds expands and vocalizations become more speech-like. Infants typically begin to produce recognizable words when they are around 12 months of age, though babbling may continue for some time afterward.

Psamtik I Pharaoh

Wahibre Psamtik I, known by the Greeks as Psammeticus or Psammetichus, who ruled 664–610 BC, was the first of three kings of that name of the Saite, or Twenty-sixth Dynasty of Egypt. Historical references for what the Greeks referred to as the Dodecarchy, a loose confederation of twelve Egyptian territories, based on the traditional nomes, and the rise of Psamtik I in power, establishing the Saitic Dynasty, are recorded in Herodotus's Histories, Book II: 151–157. From cuneiform texts, it was discovered that twenty local princelings were appointed by Esarhaddon and confirmed by Ashurbanipal to govern Egypt.

Signing Exact English is a system of manual communication that strives to be an exact representation of English vocabulary and grammar. It is one of a number of such systems in use in English-speaking countries. It is related to Seeing Essential English (SEE-I), a manual sign system created in 1971, based on the morphemes of English words. SEE-II models much of its sign vocabulary from American Sign Language (ASL), but modifies the handshapes used in ASL in order to use the handshape of the first letter of the corresponding English word. The four components of signs are handshape, orientation, location, and movement.

Oralism is the education of deaf students through oral language by using lip reading, speech, and mimicking the mouth shapes and breathing patterns of speech. Oralism came into popular use in the United States around the late 1860s. In 1867, the Clarke School for the Deaf in Northampton, Massachusetts was the first school to start teaching in this manner. Oralism and its contrast, manualism, manifest differently in deaf education and are a source of controversy for involved communities. Oralism should not be confused with Listening and Spoken Language, a technique for teaching deaf children that emphasizes the child's perception of auditory signals from hearing aids and/or cochlear implants.

Home sign is the gestural communication system developed by a deaf child who lacks input from a language model in the family. This is a common experience for deaf children with hearing parents who are isolated from a sign language community.

Indo-Pakistani Sign Language (IPSL) is the predominant sign language in South Asia, used by at least several hundred thousand deaf signers (2003). As with many sign languages, it is difficult to estimate numbers with any certainty, as the Census of India does not list sign languages and most studies have focused on the north and on urban areas.

Al-Sayyid Bedouin Sign Language (ABSL) is a village sign language used by about 150 deaf and many hearing members of the al-Sayyid Bedouin tribe in the Negev desert of southern Israel.

Turkish Sign Language is the language used by the deaf community in Turkey. As with other sign languages, TİD has a unique grammar that is different from the oral languages used in the region.

Manually coded languages are not themselves languages but are representations of oral languages in a gestural-visual form; that is, signed versions of oral languages. Unlike the sign languages that have evolved naturally in deaf communities, which have distinct spatial structures, these manual codes (MCL) are the conscious invention of deaf and hearing educators, and mostly follow the grammar of the oral language—or, more precisely, of the written form of the oral language. They have been mainly used in deaf education in an effort to "represent English on the hands" and by sign language interpreters in K-12 schools, although they have had some influence on deaf sign languages where their implementation was widespread.

There is no officially recognized national sign language in Singapore. Since Singapore's independence in 1965, the Singapore deaf community has had to adapt to many linguistic changes. Today, the local deaf community recognizes Singapore Sign Language (SgSL) as a reflection of Singapore's diverse linguistic culture. SgSL is influenced by Shanghainese Sign Language (SSL), American Sign Language (ASL), Signing Exact English (SEE-II) and locally developed signs. The total number of deaf clients registered with The Singapore Association For The Deaf (SADeaf), an organisation that advocates equal opportunity for the deaf, is 5756, as of 2014. Among which, only about one-third stated their knowledge of Sign Language.

A prelingual deaf individual is someone who was born with a hearing loss, or whose hearing loss occurred before they began to speak. Infants usually start saying their first words around one year. Therefore a prelingually deaf typically was either born deaf or lost their hearing before the age of one. Congenital hearing loss is also considered prelingually, since a newborn infant has not acquired speech and language.

The history of deaf education in the United States began in the early 1800s when the Cobbs School of Virginia, an oral school, was established by William Bolling and John Braidwood, and the Connecticut Asylum for the Deaf and Dumb, a manual school, was established by Thomas Hopkins Gallaudet and Laurent Clerc. When the Cobbs School closed in 1816, the manual method, which used American Sign Language, became commonplace in deaf schools for most of the remainder of the century. In the late 1800s, schools began to use the oral method, which only allowed the use of speech, as opposed to the manual method previously in place. Students caught using sign language in oral programs were often punished. The oral method was used for many years until sign language instruction gradually began to come back into deaf education.

Language deprivation is associated with the lack of linguistic stimuli that are necessary for the language acquisition processes in an individual. Research has shown that early exposure to a first language will predict future language outcomes. Experiments involving language deprivation are very scarce due to the ethical controversy associated with it. Roger Shattuck, an American writer, called language deprivation research "The Forbidden Experiment" because it required the deprivation of a normal human. Similarly, experiments were performed by depriving animals of social stimuli to examine psychosis. Although there has been no formal experimentation on this topic, there are several cases of language deprivation. The combined research on these cases has furthered the research in the critical period hypothesis in language acquisition.

Egyptian Sign Language

Egyptian Sign Language is a sign language used by members of the deaf community in Egypt. Although there are no official statistics on the number of deaf people or the number of people who use Egyptian Sign Language as their primary language, Gallaudet University's library resources website quotes a 1999 estimate of 2 million hearing impaired children, while a 2007 study by the WHO places the prevalence of hearing loss in Egypt at 16.02% across all age groups. Egyptian Sign Language is not formally recognized by the government.

Sign language is a language which uses visual gestures produced by the hands and body language to express meaning. It has been determined that the brain's left side is the dominant side utilized for producing and understanding sign language, just as it is for speech. In 1861, Paul Broca studied patients with the ability to understand spoken languages but the inability to produce them. The damaged area was named Broca's area, and located in the left hemisphere’s inferior frontal gyrus. Soon after, in 1874, Carl Wernicke studied patients with the reverse deficits: patients could produce spoken language, but could not comprehend it. The damaged area was named Wernicke's area, and is located in the left hemisphere’s posterior superior temporal gyrus. Signers with damage in Broca's area have problems producing signs. Those with damage in the Wernicke's area in the temporal lobe of the brain have problems comprehending signed languages. Early on, it was noted that Broca’s area was near the part of the motor cortex controlling the face and mouth. Likewise, Wernicke's area was near the auditory cortex. These motor and auditory areas are important in spoken language processing and production, but the connection to signed languages had yet to be uncovered. For this reason, the left hemisphere was described as the verbal hemisphere, with the right hemisphere deemed to be responsible for spatial tasks. This criteria and classification was used to denounce signed languages as not equal to spoken language until it was widely agreed upon that due to the similarities in cortical connectivity they are linguistically and cognitively equivalent. In the 1980s research on deaf patients with left hemisphere stroke were examined to explore the brains connection with signed languages. The left perisylvian region was discovered to be functionally critical for language, spoken and signed. Its location near several key auditory processing regions led to the belief that language processing required auditory input and was used to discredit signed languages as "real languages." This research opened the doorway for linguistic analysis and further research on signed languages. Signed languages, like spoken languages, are highly structured linguistic systems; they have their own sets of phonological, morphological and syntactic characteristics. Despite some differences between spoken and signed languages, the associated brain areas share a lot in common.

Language acquisition by deaf children parallels the development of any children acquiring spoken language as long as there is full access to language from birth.

Language deprivation in deaf and hard of hearing children occurs when a child does not receive language exposure during their critical period. Language development can be severely delayed due to the lack of stimulation and socialization. This has been observed in such well known cases as Genie, Kaspar Hauser, Anna, and Isabelle, as well as cases of feral children such as Victor. Similarly, language deprivation in deaf and hard of hearing children may occur when sufficient language exposure does not occur within the first few years of life, the critical period of language development. This is common because deaf children without hearing aids or cochlear implants cannot access the world around them through auditory means. These children often arrive at preschool or kindergarten with significant language delays that can greatly impact the rest of their education. Accommodations and specialized methods of instruction are required to meet the unique communication needs of deaf children, such as Auditory Verbal/Listening and Spoken Language therapy, cued speech, sign language, or a combination of approaches. Age of enrollment in early intervention services and strength of parental involvement are the strongest success indicators for language development in deaf children.


  1. Shattuck, Roger (1994) [1980]. The Forbidden Experiment: The Story of the Wild Boy of Aveyron. Kodansha International. ISBN   1-56836-048-7.
  2. Herodotus, History II:2, found in "An Account of Egypt".
  3. Danesi, Marcel and Paul Perron (1999). Analyzing Cultures: An Introduction and Handbook. Indiana: Indiana University Press, p. 138.
  4. McCulloch, Gretchen (2014). Slate Magazine. "What Happens if a Child Is Never Exposed to Language?"
  5. Medieval Sourcebook: Salimbene: On Frederick II, 13th Century
  6. "First Language Acquisition". Western Washington University . Retrieved 2007-02-03.
  7. Dalyell, John Graham, ed., The Chronicles of Scotland by Robert Lindsay of Pitscottie, vol. 1, Edinburgh (1814) pp. 249-250.
  8. Davidson, J.P. (2011). Planet word. London: Michael Joseph. ISBN   9780141968933 . Retrieved 1 July 2014.
  9. M. Miles, SIGN, GESTURE & DEAFNESS IN SOUTH ASIAN & SOUTH-WEST ASIAN HISTORIES: a bibliography with annotation and excerpts from India; also from Afghanistan, Bangladesh, Burma/Myanmar, Iraq, Nepal, Pakistan, Persia/Iran, & Sri Lanka, c1200-1750 Archived 2008-02-22 at the Wayback Machine .